Pneumatic tool.



C. A. HULTQUIST.

PNEUMATIC TOOL.

APPLICATION FILED JULY 3.191s.

Patented J an. 15, 1918.

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C- A HULTQUIST.

FNEUMATIC TOOL.

APPLICATION FILED JULY 3. I916.

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specification of Letters Patented J an. 15, 1913..

Application filed July 3, 1.91%. Serial No. 107,361.

To all whom it may concern:

Be it known that l, CHARLES A. Hurr- QUIST, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Pneumatic Tool, of which the following is a specification.

This invention "relates to tools operated by elastic fluid and an object of the invention is to produce a device of this character of maximum effectiveness in delivering blows.

Another object is to make provision for obtaining a cushioning effect of the piston at the end of its instroke.

Other objects and advantages will appear in the subjoined detail description.

The accompanying drawings illustrate the invention.

Figure 1 is a side elevation of a hydraulic form of tool built in accordance with this invention.

Fig. 2 is an enlarged vertical mid section of Fig. 1 on a plane normal to the line of sight, the retainer and drill being partly broken away to contract the view and the valve device being omitted.

Fig. 3 is a plan section on line indicated by w-*m Fig. 2, omitting the drill retainer.

Fig. 4 is a plan section on line indicated by -00 Fig. 2, omitting all the parts oncepting the tool retainer and the bracket supporting the same.

Fig. 5 is a plan section on line indicated by a' -.r-", Fig. 2, omitting the drill retainer.

Fig. (5 is a sectional elevation corresponding to Fig. 2 of a non-hydraulic form of the lnvention.

Fig. Z is a plan section on line indicated by m w", Figs. 2 and 6. i

There is provided a barrel comprising in the instance shown in the drawings an upper tubular section forming a cylinder 1, an intermediate tubular section 2 and a lower tubular section 3, the intermediate section 2 being provided at its upper end with reduced portion 4 to lit the bore of the cylinder 1 and the lower end of the interme diate member 2 being provided with a reduced portion 5 to fit the bore of the lower section 3. The upper end of the cylinder 1. is provided with a reduced portion 6 to hit the bore of a tubular boss 7 of a head indicated in general. by the character 8, said head forming a handle 9 by which to hold tool. The head 8 is provided with late-rally extending cars 10 and the lower barrel section 3 is provided with laterally extending ears 11, there being bolts 12 extending through the. ears 10 and 11 and provided on their lower ends between the ears 11 and the bolt heads 12 with coil springs 13 so that when the bolts are tightened up the expansive force of the springs 13 will yieldingly hold the head 8 and the barrel sections 1, 2, 3 together.

The cylinder 1 is provided with a hollow piston 14 working therein, the wall 0i. said cylinder being provided with ports 15, 16 near the opposite ends thereof to admit charges of compressed air behind and in front of the piston so as to operate said p 1ston, said ports 15, 16 communicating with a valve device 17' of any suitable construction, not shown in detail herein since the invention is not limited to the exact construction of said valve device. It sufiices to state that the valve device 17' operates to alternatively admit air to the ports 15, 16 so as to reciprocate the piston 14. The piston 14 is provided in front with a hammer 17 integral therewith having a portion 18 of square cross section fitting in a square hole 19 of a bushing 20 which is rotative in the lower barrel section 3 and is provided with an annular shoulder 21 fitting against a complementary annular shoulder 22 in the inside oi the lower barrel section 3, said shoulders serving to retain the bushing against downward movement and the re duced portion 5 of the intermediate section 2 preventing any substantial upward move ment of said bushing.

The hammer 17 is provided with longitudinally extending channels or grooves 23, the upper ends of said channels being slightl spaced apart from the front end of the piston and the lower ends out said channels communicating with downwardly and inwardly sloping ducts 24 which in turn a communicate with. an. axially extending duct 25 that leads to and opens through the lower end of the hammer 17. The duct 25 communicates with the upper end of a duct 26 which extends axially from end to end of a bit or boring tool 2?, the upper end of which may be of hexagonal or other angular cross section and tits in the bushing 20 so that on the out strolre oi the piston 1d the hammer 1'?" will strike the bit 27' to cause said bit to act on the material in which it whereupon the air passing through the duct 26 blows away said material as is well understood in the art.

The rear end of the piston 14 is provided with a socket 28 into which is screwthreaded a bushing 29, the inner face of said bushing being provided with rifling or spiral grooves 30 to receive threads or tongues 31 extending spirally in the periphery of a stud 32 that extends through an axial orifice 33 in a cylinder head 34 resting against the upper end of the cylinder 1 inside of the tubular boss 7. The stud 32 is provided with an enlarged portion 35 having pawls 36 pivoted thereto, said dogs being pressed outward by pins 37 projecting from spring chambers 38 which accommodate springs 39 for forcing the pins outward so as to hold the dogs in engagement with ratchet teeth 40 on the inside face of aratchet ring 41 which is frictionally held against rotation between the adjacent faces of the cylinder head 34 and a plate 42 resting against the inner end of the bore of the tubular boss 7 and provided with an orifice 43 to accommodate the upper end of the stud 32.

The pawls 36 and teeth 40 are so arranged that downward movement of the Piston 14 causes the stud 32 to rotate relative to the ratchet ring and that upward movement of the piston causes the piston to turn relative to the stud which is held against turning by the ratchet pawls and teeth.

Turning of the piston 14 of course causes the bushing 20 to turn to rotate the bit 27 so that on successive down strokes of the bit said bit will have its cutting edge presented at different angles in the hole being drilled as is well understood in the drilling art.

The tool is provided near its lower end with means to prevent thebit from falling out of the bushing 20 and said means will now be described. Between the upper end of the lower barrel section 3 and a shoulder 44 of the intermediate barrel section 2 there is provided a bracket 45 havin an orifice 46 to fit the reduced portion 5 o the intermediate section 2. The bracket 45 is provided with downwardly extending lugs 47 havingperforations 48 to pivotally hold the outwardly bent ends, forming pivots 49, of arms 50, said arms being joined together at their lower ends by a semicircular abutment 51 adapted to partly encircle the bit 27 in alinement with the shoulder 52 of the bit so that outward movement of'the bit will be limited by engagement of the abutment 51 with the shoulder 52. The arms 50 when in position parallel to the axis of the tool and therefore in bit-retaining position are held against swinging away from said position by reason of the outer faces of said arms engaging grooves 53 on the inner faces of the lugs 47. The arms 50 are of spring material and it is clear that by the construction just described said arms cannot become accidentally detached from the bracket 45 but may readily be turned, when sprung out of the grooves 53, so as to bring the abutment 51 to one side of the device to permit removal of the bit 27 when such removal becomes desirable.

The bit-retaining means are not claimed herein but are the subject matter of my copending application for patent for drill steel retaining device, Serial No. 157,350, filed March 26, 1917.

The foregoing described construction applies to both forms of the invention and the features of construction of the form shown v in Figs. 1- to 5 inclusive differentiating from that shown in Fig. 6 will now be described.

The duct 25 of the hammer 17 is extended axially upward at 54 and communicates with the lower end of the socket 28 in which the bushing 29 is seated. The duct 25, 54 is provided with a tube 55 fitting said duct above the level of the ducts 24 when the hammer is raised and having a portion 56 of reduced diameter extending therefrom downward and projecting beyond the lower end of the hammer into the upper end of the duct 26 of the bit 27 so that there is an annular space a extending from the ducts 24 to the lower end of the reduced tube portion 56 between said tube portion and the walls of the hammer and bit.

By having the tube 55 thus connected with the socket-engaging 'end of the stud 32, it is clear that said tube may be made of minimum length, thus minimizing cost of said tube and cost of replacing the same when the substitution of a new one for the old becomes necessary or advisable.

The upper end of the tube 55 is screwthreaded into a nipple 57 which in turn is screw-threaded into the lower end of the stud 32, there being an axial duct 58 in the stud 32 communicating at its lower end with the nipple 57 and opening at its upper end through the upper end of said stud. The upper end of the duct 58 is provided with a nozzle 59 which is tightly fitted and fastened in the orifice 43 of the plate 42. The boreof the nozzle 59 registers with a port 60 in the head 8, said port extending for a portion of its length axially of said head and thence laterally into a' screw-threaded opening 61 adapted to be connected to a suitable source of water supply under pressure as is well understood.

Special attention is directed to the simple and reliable construction just described for admitting water to the duct 26 of the bit 27, the construction being such that leakageof water is reduced to a minimum.

It is noted that by reason of the air being conducted through the grooves and through Was - avoided.

the duct 25, 54 around the tube 55 into the cylinder behind the piston the piston 14 will be cushioned on itsin-stroke by the-air in the cylinder between the cylinder head 34 and the rear face of the piston when the piston has moved to the position to close the air port '15. This is very important as the air admission valve device does not always function quick enough in this class of tools to admit air behind the piston soon enough to cushion said piston.

'By the construction described the use of packing to obtain water tight joints is The foregoing-will enable those skilled in the art to which the invention appertains understood that changes may be made within the spirit and scope of the appended claims and that the elements in said claims are subject to the doctrine of equivalents.

I claim:

1. A pneumatic tool comprising a barrel forminga cylinder, a piston in the barrel having an axial socket, a hammer on the piston having an axial duct and having a longitudinally extending ,groove in its periphery and having another duct connecting one end ofsaid groove to the axial duct, the other end of said groove opening into the cylinder, means to admit compressed air alternatively in front and behind the piston, a tube projecting into the axial duct and a stud projecting into the socket so that the piston can move relative to the stud, said stud being connected to the socket-engaging end of the tube and having an axial duct communicating with the tube.

2. A pneumatic tool comprising a barrel forming a cylinder, a piston in the barrel having an axial socket, a hammeron the piston having an axial duct opening through its lower end and communicating with the interior of the cylinder, means'to admit compressed air alternatively in front and behind the piston, a tube pro ecting into the axial duct, and a stud projecting into the socket 'so that the piston. can move relative to the stud, said stud'being connected to the socketengaging end of the tube and having an axial duct communicating with. the tube.

3.- A pneumatic tool-comprising a barrel forming a cylinder, a piston in the barrel having an axial socket, a hammer on the piston havin an axial duct opening through its lower; en and communicating with the interior of the cylinder, means to admit compressed air alternatively in front and behindthe piston, ahead connected to the bara stud -mounted in p the head and projecting into the axial socket and provided with an axial duct, a nipple screw-threaded into the duct at the socket-engaging end of the stud, and a tube fastened to the nipple and extending into the axial duct of the hammer.

4. A. pneumatic tool comprising a barrel forming a cylinder, a piston in the barrel having an axial socket, a hammer on the piston having an axial duct opening through its lower end and communicating with the interior of the cylinder, means to admit compressed air alternatively in front and behind the piston, a head connected to the barrel, a stud mounted in the head and projecting into the axial socket and provided g with helical tongues and provided with an axial duct, there being helical grooves in the wall of the socket to fit the helical tongues, a ratchet connection between the stud and head to allow said stud to turn in one direction to hold it against turning in the opposite direction, and a tube extending into the axial duct ofthe hammer and connected to the socket-engagin end of the stud and communicating wit the axial duct of the stud.

5. A pneumatic tool comprising a barrel having a cylinder provided with air ports, a piston in the cylinder having a socket, a stud connected with the barrel and extending into the socket, and a water tube connected to said stud, said stud having a duct at the socket-engaging end communicatin of said stud wlth. said tube.

6, A pneumatic tool comprising a barrel forming a cylinder having air ports, a piston in said cylinder provided with an axial socket, a hammer on the piston, a head connected to the barrel and provided with a port, a stud mounted in the head and projecting into the axial socket of the piston and provided with an axial duct and provided with an enlarged portion, said axial duct communicating with said socket, a plate between said enlarged portion and the head, a nozzle fastened in said plate and projecting into the duct in the stud and communicating with the port in the head, and a water tube fastened to the socket-engaging end of the stud and communicating with the duct in the stud and projecting into the duct in the hammer.

Signed at Los Angeles, 24th day of June, 1916.

CHARLES anumourtr.

California, this tit) 

